[BioC] expresso ( medianpolish & pmcorrect="subtractmm") Issue

[Sundaram, Shyam (NIH/CIT)]

Hi:
I thought I would like to share a situation that I have been facing. It is
not a bug but something that happens in a specific condition. When you use
the "medianpolish" method in "expresso" and also use the "subtractmm" option
in the "pmcorrect" option you will find that the method will blow up. The
reason for this is sometimes the PM-MM will yield "negative" values and this
will cause the "NaN" values.

I guess is it good to have the ability to choose the transformation function
to something other than log2 for negative values.

Any suggestions/thoughts on this.

Thanks
Shyam